1. Field of the Invention
The present invention relates to an inkjet recording apparatus in which ink droplets are ejected to print.
2. Description of Related Art
An inkjet head included in an inkjet printer for printing on a recording medium by ejecting ink droplets includes a passage unit on which nozzles are formed for ejecting ink droplets and in which pressure chambers are formed which are connected to the respective nozzles; a piezoelectric actuator for giving ejection energy to ink in each pressure chamber; and a driver IC for outputting a driving signal to drive the piezoelectric actuator. The piezoelectric actuator serves to change the volume of each pressure chamber and thereby give pressure to ink in the pressure chamber. Japanese Patent Unexamined publication No. 2002-36568 discloses an piezoelectric actuator including a piezoelectric sheet positioned over a plurality of pressure chambers; individual electrodes positioned to be opposed to the respective pressure chambers; and a common electrode fixed at a reference potential and positioned to be opposed to the individual electrodes through the piezoelectric sheet. When the driver IC of the piezoelectric actuator gives a driving pulse signal to an individual electrode of the actuator, an electric field is generated at the portion of the piezoelectric sheet sandwiched by the individual electrode and the common electrode, along the thickness of the sheet. As a result, the thickness of that portion of the piezoelectric sheet increases to decrease the volume of the corresponding pressure chamber, and thereby pressure is given to ink in the pressure chamber.